160 LABORATORY GUIDE IN PHYSIOLOGY. 



() How many steps may be made out with the 

 means used and under the conditions existing in 

 the experiment ? 



(V) In what order do the changes occur? 



(13) Place some starch paste in a beaker which may be 

 floated in ice water; similarly float a beaker with 

 saliva. After both liquids have been cooled down to 

 near the temperature of the surrounding water, mix 

 them in one of the beakers; keep the mixture at the 

 low temperature while subjecting portions of it every 

 two minutes to the tests suggested above. 



(a) May the same changes be made out in this ex- 

 periment as in the previous one? 



(^) Are the changes in the same order? 



(<r) State any differences in salivary digestion at 

 blood temperature and at the low temperature 

 (0C) used in this experiment. 



(14) (a) Sum up the day's work in a series of conclu- 

 sions. 



(/;) What is the chemical formula of starch ? Of 

 erythro-dextrin ? Of maltose? Of dextrose? 



(<:) Write a chemical reaction or a series of reac- 

 tions which will be in harmony with the observa- 

 tions and show as nearly as possible the course of 

 salivary digestion. 



(</) What change has the ferment wrought in the 

 starch molecule to render the resulting carbohy- 

 drate capable of diffusion through animal mem- 

 brane ? 



